Arizona opened up backyard casitas, but every city wrote its own version — and a few kept a second, roomier category most people have never heard of. Pick your city and see what you can actually build.
The number that moves the most is the size cap — and whether the city still recognizes a guest house as something separate from an ADU.
| Jurisdiction | Biggest you can build | Guest house ≠ ADU? | How many |
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The state law that opened casitas up applies to cities and counties — not to HOAs. Your CC&Rs can still prohibit a detached structure, a second dwelling, or a rental, and they remain enforceable after the city has approved your permit. You can get a fully approved building permit and still be in violation the day you break ground.
Read your CC&Rs before you spend a dollar on drawings. If your HOA allows it subject to architectural review, we sequence that approval alongside the city submittal so you're not paying to draw something twice.
Setbacks, easements, utility runs, lot coverage, and where your existing structures sit decide what actually fits back there. Send us the address and we'll tell you what your property will support.
Don't see your city above? Send it anyway — we permit across 40+ Arizona jurisdictions and we'll confirm your rules directly.
We'll look at your lot and your city's rules and get back to you with a straight answer, usually same or next business day.
Call 480-660-3133Enter your address and our system checks your city's rules and emails you a written report on what your lot will support — size, setbacks, and next steps.